Art of stretching sheet material.



L. S. LAGHMAN; ART OF STRETGHING SHEET MATERIAL. APPi-IOATION FILED JUNE 9, 1910.

Patented Aug. 11, 1914,

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LA RENCE s. LACHQMANLOF NEW YORK, N. Y.

ART OF STRETCHING SHEET MATERIAL.

, Specification of Letters Patent.

Patented Aug. M, 1914.

Application filed June 9, 1910. Serial No. 566,052.

To all whom it may concern Be it known that I, LAURENCE S. LACH- MAN, a citizen of the United States, and a resident of the city, county, and State of New vYork, have invented certain new and useful Improvements in the Art of Stretching Sheet Material, of which the following is a specification. v

This invention relates broadly to certain improvements in the art of stretching sheet materials, forming the body of a reinforced object.

It more specifically relates to certain im' provements in diaphragms, adaptable for use in phonographs, telephones, etc., and to the art of producing the same, and for this reason it is particularly illustrated, and will be particularly herein described, with reference to diaphragms. It is to be understood, however, that in its broader aspects it is not to be construed as restricted to such diaphragms, and that the latter is selected for illustrative purposes and because of pecul-' ia-r advantages which the process and product possesses in their relation to said particular class of devices.

The invention consists broadly'of a process of producing an article having a body of stretched material and a reinforcing frame, comprising the steps of securing the body and frame together and subjecting the frame to pressure which stretches the body; and to the product thereof.

The invention also consists in producing articles having reinforced peripheral portions and a body of sheet material eo-mpris ing the steps of securing to each other, in a proper relation. :1 frame forming such reinforcement, and a body of suitable sheet material, and then stretching the. latter by means of pressure adapted to change the form of the frame and to cause it while undergging such change to transmit to the body a pulling force tending to disrupt the same.

The invention further consists in the product of such process.

The invention also consists in a diaphragm for phonographs, telephones or analogous apparatus or devices, consisting of a body of stretched sheet material, as metal, celluloid, etc, having a reinforced edge; and further in a process of producing the same my mventiom'with a part of the material of the body broken away. Fig. 2 is a vertical sectional view illustrating an initial po sition of the body and frame. F ig. 3 is a similar sectional view illustrating an initial position of the parts when the frame is of one difierent form from that of Fig. 2. Fig. 4 is a sectional view through a diaphragm produced from the parts illustrated in Fig. Fig. 5 is a similar view illustrating an initial position of the partswhen the frame has still another form; and Fig. 6 is a similar view illustrating the completed diaphragm when the frame of Fig. 5 is employed.

The body element, marked 1 in Fig. 1, may be of any suitable sheet material, shape and size, and the frame, marked Qin the same. figure, similarly may be of any suitable material and size, and of any suitable open form. For diaphragms for phonographs or telephones, it is 'n'eferred that the body of sheet steel. though other sheet metal and even materials, such as celluloid, which are capable of'being stretched or expanded by the process hereinafter set forth and are properly responsive when stretched to the vibrations of a sound re'eori'liug or reproducing tool of a phonograph, or to the sound waves or electrical impulses of a telephone receiver or transmitter, may be employed if desired. Preferably, the body is of circular form and the frame of annular form.

In the practice of the process, the frame is first mounted on the body in a suitable relation therewith and. after they have been rigidly secured together so that outward movement of the frame at its place or places of contact with the body will tend to dis rupt the latter, pressure adapted to change the form of the frame is applied. said frame during said change obviously stretching said body lightly within the frame.

Referring now to the several forms exemplifying various embodiments of my invention:Fi. 9 illustrates a form in which the frame marked A is primarily a dishshaped annulus having its outer peripheral edge superimposed on the body, marked B, contiguous to the peripheral edge of the latter, and secured thereto at b. In the practice of this particular embodiment of the process, the frame is pressed down until its under surface is in contact with the upper su face of the body, the latter retaining its flat shape. In its described movement, it obviously exerts outward ressur on the body, pulling the l tter uniformly at all points around its periphery, thereby stretching it to a substantially uniform extent throughout.

In the embodiment shown in Figs. 3 and,

4, the primary shape of the frame, marred;

A, is that of a flat ring3hhd the shape of the body, marked i3, is that of a flat disk. When these "parts are superimposed, with "the contiguous surfaces in con. tact and suitably secured together, pressure is applied which changes the shape of the; frame to that of a dish-shaped annulu .the%

shape of'the outer portion of the may I "sing similarly changed and hereby becoming stretched within the limits defined by the inner aeriipheral edge or the frame.

In tie form shown in Figs. 5 and 6, the primary shape of the frame, marked A, is that of a vertically disposed ring "superimposed edgewise on the surface bf the body, marked B and has a peripheral flaiwc b? which encircles the Outer surface of the ring and is suitably secured thereto. In the iraetiee of the process this ring is flattened down toward the body, stretching the latter by exerting outward pressure upon the angle 6 4 The contacting portions of the body and frame, particularly the forms shown in Figs. 2, 3 and 4; are preferably integrally secured together, as by welding, electrlcally or otherwise, by brazing, or by soldering, electric welding being preferred. This 1s also true ofthc contacting portions of the body and frame of Figs. 5 and 6, but is not so important with respect to the latter form as the engagement of the flange of the body forms a securing means which is more or less effective in holding the parts.together both during the formation of the articles and after the latter have been formed.

It is'belici'cd that my invention will be fully comprehended from the foregoing, and

that it will be seen that it produces important advantages in the art of stretching metal and particularly in the art of producing diaphragms, as well as in the diaphragms themselves.

While I have shown the elements A, A' and A separte from the elements B, B and said elements may be an integral part thereof, the thickened part to be formed in any desirable way as an integral part of said diaphragm'or element B, B or B \Vhile the device as illustrated is in the form of a disk, it is tobe understood that it may also be in any other desirable shape.

Having now described the invention that I believe to be new and desire to secure by Letters Patent, is:

1. The process herein described, which nently securing an. open frame and a sheet of expansible material together and subjecting the frame to pressure to change its shape and stretch the '5 feet.

2. The armers herein described, which compi'ises the steps of securing an open frame and a sheet of expansible material together, and subjectingthe fram'eto pres: sure which changes its form and causesit while assuming the new form to stretch the sheet. 7

The process herein described, which comprises the steps of permanently securing together a sheet of suitable material and a reinforcing frame therefor, and subjecting the frame to pressure which changes its form and causes it while assuming the new form to stretch the sheet.

4. A process of making diaphragms, consisting of a body of sheet material and a reinforcing frame therefor, comprising the steps of permanently securing thesheet at its edges to the frame and first subjecting the frame to pressure to stretch the sheet.

5. A process of making diaphragins consisting of a stretched body of sheet material and a reinforcing frame therefor, comprising the steps of pernianei'itly securing the body and frame together and subjecting th frame to pressure which changes its form and stretches the sheet 6. A process ofunaking diaphragrns con-a sisting of a stretched body of sheet material and a reinforcing frame, comprising the steps of securing a dish-shaped reinforcing annulus to a body of sheet material, and subjectingiithe annulus to pressure which forces it toward the plane of the body and stretches the latter.

7. A process of making diaphragms, consisting of a stretched body of sheet material and a reinforcing frame, comprising the steps of securing a dish-shaped reinforcing annulus to a body of sheet material, subjecting the annulus to pressure which forces it toward the plane of the body into flatwise engagement therewith, and then subjecting the parts to further pressure which changes the form ,of their secured portions.

8. A process of makingj'diaphragms consisting of a stretched body of sheet metal comprises the steps of rigidly and pern1a-,

B, respectively, it is to be understood that 5 iio and a reinforcing ring therefor, comprising puts it into #1 reinforcing relatifln with the the steps of permanently securing the body latterand ring together and subjecting the ring In Witness whereof I have hereunto set to pressure which changes its form and my hand at New York, county of New York 5 stretches the sheet. and State of New York, this seventh day of 5 9. A process of making diaphragms which June, 1910. comprises the steps of welding together co11- LAURENCE S. LACIE/IAN. tactmg portions of a body 0i sheet metal In presence of-- and a frame and then subjecting the frame ISABEL R. RICHARDS, .0 to pressure which stretches the body and JOHN J. RANAGAN.

Copies of this patent may be obtained. for five cents each, by addressing the "Commissioner of Barents, Washington, 3. Q. 

